Symptoms and diagnosis of schizophrenia

The Schizophrenia is a mental disorder , with a worldwide lifetime risk occurs from about 1%. The disease has a variable course and begins in the majority of patients before the age of 35. The cause of the disease is unknown. The appearance of schizophrenia is characterized by positive and negative symptoms, which manifest themselves differently in the different stages of the disease. This article gives an overview of the forms of illness-related experience and behavior of patients with schizophrenia (symptoms) as well as the process of correctly recognizing the disease ( diagnosis ).

Due to the diversity of schizophrenia as a group of diseases (Bleuler) , a uniform description of symptoms is not possible. There are also no cardinal symptoms of schizophrenia in the strict sense, as the cause of the disease is unknown. In the course of time, different disease concepts of schizophrenia have been developed, each with its own emphasis on certain symptoms.

Basics

The basics of a diagnostic psychiatric process can be summarized under the general keywords of psychiatric examination and assessment and psychiatric diagnosis and classification. The psychiatric examination includes conversation, psychopathological findings and various examination levels. A wide variety of survey instruments were developed to structure this. For the German-speaking area, the AMDP system should be mentioned here in particular . The psychiatric classification now knows two important classification systems, the ICD of the World Health Organization and the DSM-5 of the American Psychiatric Association . Special survey instruments have been developed for classificatory diagnosis. The structured clinical interview for DSM-IV (SKID) is used for classification according to the DSM and the "International Diagnostic Checklist" serves as a checklist for classification according to the ICD system. "DIA-X" is a survey instrument that is suitable for both classification systems.

Symptoms and Signs of Schizophrenia

The illness-related experience of patients with schizophrenia is very diverse. A distinction is made between non-specific symptoms and characteristic symptoms. Nonspecific symptoms are not only found in schizophrenia, they therefore do not help in recognizing the disease. But they can be a measure of the severity of the disease. Characteristic symptoms are those that are often found in schizophrenia. A distinction is made between characteristic symptoms for the different phases of the disease and characteristic symptoms for different types of schizophrenia . Among the characteristic symptoms in the course of the disease, a distinction is made primarily between the positive or plus symptoms , which characterize the acute phase of schizophrenia, from the negative or negative symptoms , which can be predominant in the entire course of the disease. The predominant symptoms of the subtypes of schizophrenia can be summarized under the keywords delusions for paranoid schizophrenia, affective changes and disorganization of thinking for hebephrenic schizophrenia and psychomotor disorders for catatonic schizophrenia. Finally, a distinction can be made between disease characteristics that can only or mainly be inferred from a report by the patient (hearing voices) and those that can only or mainly be inferred by observation (rigid movement). Following Kurt Schneider's suggestion, Gerd Huber differentiates between abnormal modes of experience and abnormal expression in his textbook. This distinction reflects the conceptual difference between clinical symptoms (patient complaints) and clinical signs (findings from a physical examination).

Nonspecific mental symptoms

There are a number of unspecific symptoms in schizophrenia. Such symptoms do not allow a diagnosis of the disease. They occur with other conditions too, and the fact that a person has such symptoms does not mean that they have schizophrenia. But many patients with schizophrenia show non-specific symptoms in addition to the characteristic symptoms of the disease. A system of the unspecific symptoms of the disease can be done in various ways.

Outpost symptoms of schizophrenia

One way to classify the unspecific symptoms of schizophrenia is to identify the outpost symptoms of the disease. These outpost symptoms, or common early signs of the disease, have been identified in studies of the onset and early course of schizophrenia . The most common symptoms in the early course of schizophrenia are: restlessness, depression, anxiety, thinking and concentration disorders and worry. Other investigators found restlessness in 72% of those affected, sleep disorders in 64%, nervousness in 62%, difficulties at work in 60% and the feeling of not being understood in 56% as frequent early warning signs.

Common general symptoms in schizophrenics

Another possibility to classify the unspecific symptoms of schizophrenia is realized in scales for recording the psychopathological findings. A frequently used scale is the Positive and Negative Syndrome Scale ( PANSS ). In addition to seven positive and seven negative symptoms, it also contains a list of sixteen unspecific symptoms such as fear, feelings of guilt, concern about physical integrity or disorder of will.

Characteristic signs of mental illness

There are various ways of classifying the characteristic psychological symptoms of schizophrenia: according to the positive-negative concept, according to the symptoms of acute and chronic schizophrenia, according to frequently occurring symptoms or in the sense of the first-class symptoms according to Kurt Schneider.

The symptoms of schizophrenia can be divided into two groups of positive and negative symptoms . The positive symptoms are those that are particularly evident in the event of an acute episode of the disease, and the negative symptoms are those that often appear as a permanent feature of the disease. The so-called "six A" according to Andreasen are considered negative symptoms: Affect flattening, alogy (speech impoverishment), abulia / apathy (lack of will), anhedonia (inability to feel positive feelings), attention disorders and antisociality (disruption of the ability to communicate). The most common positive symptoms are: delusions , hallucinations , thought disorders and ego disorders . Although the dichotomous model of schizophrenia presented by Nancy Andreasen in this work did not stand up to critical review, the introduction of the positive-negative concept in schizophrenia research was extremely successful.

If, according to Tim Crow, schizophrenia is divided into type I and type II schizophrenia , then the symptoms are classified according to whether they occur predominantly in the acute or in the chronic phase. The most common symptoms of the acute phase include a .: Lack of insight into the disease, acoustic hallucinations and delusions. The most common symptoms of the chronic phase include a .: social withdrawal, lack of drive and language impoverishment. However, this classification of schizophrenia could not be replicated in subsequent empirical studies.

The first-line symptoms of schizophrenia according to Kurt Schneider are:

• Delusional perception ,
• the dialogic and commentary acoustic hallucinations
• Thought input , thought withdrawal , thought spreading and will-influencing,
• other influencing experiences with the character of what is made from outside (e.g. physical influencing experiences).

The empirically most frequent symptoms of schizophrenia are: disorders of thinking and language (here especially the lack of thought experience), disorders of affect (flattening of affect and depression), hallucinations (dialogical and commenting voices), delusions (e.g. paranoia) and ego Disturbances (the so-called disturbances of the imbalance of experience).

By examining groups of symptoms, various investigators have put forward hypotheses for a subclassification of schizophrenia, which should replace the old Kraepelin classification system (paranoid, hebephren, kataton). Surprisingly, almost all attempts to replace the old system of subtypes have proven unsuitable. The concept of syndrome clusters according to Liddle ( distortion of reality, psychomotor impoverishment and disorganization) appears to various authors to be more promising, as it supports the empirical evidence and clinical observation that schizophrenic patients can show symptoms of the various subtypes alternately in the course of their illness.

Experience and expression

Based on Kurt Schneider, Gerd Huber differentiates between abnormal experience and abnormal expression. According to Schneider, symptoms of the first rank, which are also found as symptom group 1–4 in the ICD-10, are considered to be the abnormal mode of experience of the schizophrenics. The table gives an overview modified according to Huber:

Symptoms of the first and second rank according to Schneider

Abnormal experience	Symptoms of the first order	Second rate symptoms
Acoustic hallucinations Body hallucinations Other hallucinations Schizophrenic ego disorders Delusion	Dialogic voices, commenting voices, sounding thoughts Bodily influencing experiences Thought inspiration, thought withdrawal. Spreading thoughts, influencing the will Delusional perception	Other auditory hallucinations Coenesthesia in the strict sense Optical hallucinations, olfactory hallucinations, taste hallucinations Simple personal relationship, crazy idea

Expression symptoms in the broader and narrower sense

Expression symptoms in a broader sense	schizophrenic expression disorders in the strict sense
Formal thought disorder: (deep thought and breaking off). Catatonic Disorders Affect and contact disorders Expression disorders in the strict sense	Psychomotor: "loss of grace" Facial expression: "Paramimie" Linguistic expression: neologisms, patchwork words, quirky language Holistic distortions of expression: distant or bizarre behavior

Physical symptoms and signs

Patients with schizophrenia show certain physical symptoms, so-called “neurological soft signs” (non-localizing neurological signs). Above all, they include disorders of complex movement patterns , but also abnormal involuntary movements and intermittent saccades. The evaluation of such phenomena as the disturbed eye movement in schizophrenic patients and their close relatives is controversial. Some authors have suggested that it is a so-called intermediate endophenotype , a disorder that is genetic and is closely linked to the physiological cause of schizophrenia. However, this hypothesis is controversial, although the concept of endophenotypes is very popular in the context of neurobiological research into the causes of schizophrenia.

Technical examination results

→ Main article : Neurobiological concepts of schizophrenia

As a general rule, patients with schizophrenia do not show any abnormalities during technical examinations. According to the diagnostic criteria of the ICD, physical health is a prerequisite for the diagnosis of schizophrenia. The exceptions to this rule are discussed in detail in the main article mentioned above. Irrespective of this, it is not uncommon to find changes in the blood count due to concomitant diseases in patients who have been ill for a long time and show a chronic form of the disease. Neuroleptics can cause slight increases in liver values. Some patients show behavioral abnormalities (e.g. delusional-induced polydipsia ), which are then reflected in changed laboratory values ​​(in the case of polydipsia, a decrease in serum sodium levels).

The operationalized diagnosis of schizophrenia

In order to understand the diagnostic process of schizophrenia (as for all mental illnesses) according to ICD - or DSM-5, one must know some basic principles of current classification systems in psychiatry.

These are:

• The concept of operationalized diagnostics
• The phenomenon of comorbidity
• The principle of multiaxial diagnostics

Operationalized diagnostics

In order to be able to carry out an operationalized diagnosis for a disease, one needs two things: firstly, diagnostic criteria, i.e. symptoms, signs, findings, time and progress criteria in the sense of inclusion and exclusion criteria; second, decision-making and association rules for these criteria.

The symptom criteria are precisely described in textbooks on psychopathology or in the handbooks and manuals for psychiatric scales and are often different from everyday language usage. The terms used, such as “episode” or “disturbance” are also subject to precise definitions and must not be confused with everyday terms. The operationalization takes place with varying degrees of rigor, for example stricter criteria are applied for research purposes.

For schizophrenia, the ICD catalog differentiates between general diagnostic criteria for schizophrenia and a reservation of exclusion. Diagnostic criteria are then prescribed for the subtypes of the disease (paranoid, hebephrenic, kataton and undifferentiated), as well as for postschizophrenic depression, the schizophrenic residual and schizophrenia simplex. Rules for the progression images are also given.

According to ICD-10, the diagnostic algorithm for schizophrenia provides the following. A time criterion is first defined: the symptoms must be present continuously for at least one month. Two sets of symptom groups are then defined. The first row includes symptom groups 1 - 4. The second row includes symptom groups 5 - 9. The content of symptom group 1 - 4 according to the ICD-10 largely corresponds to the first-class symptoms according to Kurt Schneider.

Finally, a reservation of exclusion is defined. Schizophrenia should not be diagnosed if the constellation of symptoms suggests pronounced manic or depressive states. (Differential diagnosis or differential typology according to K. Schneider against other "endogenous psychoses") or if there is a somatic brain disease ( tumor ) or if there are indications of intoxication or substance withdrawal as the cause of the symptoms (differential diagnosis against physically induced disorders = "organic psychoses")

The algorithm then reads: If a clear symptom of symptom group 1 - 4 or two clear symptoms of symptom groups 5 - 9 have been present for at least one month and no exclusion criteria are found, the diagnosis of schizophrenia may be made.

For schizophrenia, the disease is then assigned to the subtypes according to the ICD and the progression is classified using eight different rules. An operationalized ICD diagnosis of schizophrenia can look something like this:

• If a patient exhibits a culturally inappropriate delusion for at least a month (symptom of symptom group 1 - 4),
• If symptoms of the other subtypes are in the background (e.g. catatonic symptoms),
• If the exclusion criteria are met,
• If the symptoms have relapsed repeatedly over several years and
• If the patient was symptom-free or with few symptoms between the acute phases of the disease, the diagnosis is:
• Paranoid schizophrenia (subtype No. 1) F 20. 0
• Episodically remitting (course criterion No. 3). x3.

The full notation is then: Paranoid schizophrenia, episodic remitting (ICD-10 F 20. 03)

Comorbidity

The term comorbidity means the common occurrence of different diseases. The diagnosis rules of the ICD-10 require that no symptom be omitted because it does not fit a diagnosis, but rather makes as many diagnoses as are necessary to depict all the symptoms found. This procedure is by no means self-evident, which only becomes clear in comparison with historical concepts such as Karl Jasper's layer rules.

In modern diagnostic systems, assumptions that are obvious but cannot be empirically proven are abandoned. The reasons for this are diverse:

• Patients with multiple diseases are more seriously ill and their prognosis is poorer.
• The comorbidity can provide clues about the etiology of a disease.
• If you leave the shift rule, the prevalence figures change : Certain diagnoses then occur more frequently.

The introduction of the concept of comorbidity has shown that certain illnesses (e.g. addiction or personality disorders) often occur in combination. This phenomenon is explained in different ways, for example, that comorbid diseases are the result of a certain other disease (example: addiction as a result of fear), that the comorbidity points to common causes of different diseases (example: fear and depression) or that the comorbidity is an artifact due to fuzzy diagnostic criteria or faulty diagnostic algorithms (example: dependent personality and social phobia).

Multiaxial diagnostics

The basic idea of ​​multiaxial diagnostics in psychiatry is the consideration to present all living conditions that contribute to the course of the disease in a formalized way. Kraepelin's concept of " pathoplastic " conditions took account of the fact that such living conditions are of great importance . In the modern multiaxial approaches this is done systematically.

Historically, there are three precursors to multiaxial diagnostics:

• Kretschmer's considerations on multi-dimensional diagnostics,
• The two-axis system (symptom and etiology) by Essen-Müller and Wohlfahrt from 1949.
• The multi-axis system from Rutter from 1969.

There are many approaches to multiaxial diagnostics and no agreement as to which axes are necessary. For this reason, only the multiaxial approach according to ICD-10 is presented here. The ICD-10 has three axes for mental illness. Axis I describes the clinical diagnoses, axis II the so-called psychosocial functional limitations and axis III problems of lifestyle and coping with life. The DSM knows five axes. Axis I-III corresponds to the clinical diagnoses of the ICD-10, axis V covers the level of social functioning and axis IV psychosocial and environmental problems. The axes of the ICD and DSM are compared in the following table.

Multiaxial systems

ICD-10	DSM-IV-TR
Axis I: clinical diagnosis of mental disorders. Axis I: clinical diagnosis of personality disorders and intellectual disorder. Axis I: clinical diagnosis of physical diseases. Axis II: degree of social adaptation or disability. (WHO DAS-S) Axis III: psychosocial factors and environmental factors. (according to ICD-10 Z)	Axis I: clinical disorders. xxx Axis II: Personality disorders and intellectual disabilities. Axis III: medical disease factors. Axis V: Assessment of the functional level (GAF) Axis IV: Psychosocial and environmental problems.

The results of the axis assessment can now be presented on the one hand as ICD diagnoses and on the other hand as numerical values ​​using scales.

• Axis I: ICD-10 F 20.00 (paranoid schizophrenia, continuous)
• Axis II: Global Assessment of Functioning Scale of 50, analogous values ​​for the WHO Disability Diagnostic Scale.
• Axis III: ICD-10 Z56. 0 (unemployment); ICD-10 Z60. 2 (person living alone); ICD-10 Z 59. 6 (low income)

In this way it is possible to systematically record important circumstances that show the severity of an illness. In addition, the formalization makes it possible to evaluate the recorded data with the aid of a computer and to compare it for studies. Multiaxial approaches are indispensable for psychiatric research today.

The main problem with multiaxial diagnostics is the diversity of the systems and the lack of consensus on the use of the different types. This limits the value of the methods, namely their comparability for scientific studies. In addition, some axes show overlapping content and are therefore not independent of one another.

Differential diagnosis

The differential diagnosis of schizophrenia is multifaceted. In general, one assumes the following assumption: Schizophrenia is always a psychosis, but not all psychoses are schizophrenia. The core question can then be formulated in which diseases the most common positive symptoms of schizophrenia (delusions and hallucinations) can also occur and how such diseases can be differentiated from schizophrenia. Schizophrenia should be differentiated from substance-induced psychoses, somatic diseases and other mental disorders.

Differential diagnosis against somatic and substance-induced disorders

In this sense, the ICD catalog defines that schizophrenia should not be diagnosed if the psychotic symptoms occur as a result of intoxication or withdrawal (alcohol, drugs, medication) or are accompanied by a physical brain disease ( epilepsy , brain tumor , Traumatic brain injury , infection of the central nervous system etc.). Here the differential diagnosis is made by excluding a physical illness. The guideline of the differential diagnosis is therefore that the diagnosis of schizophrenia should only be made if the patient in question is physically healthy and does not take any psychotropic substances.

Differential typology versus other mental disorders

Schizophrenia is then differentiated from other mental disorders. According to K. Schneider, the differentiation from other psychoses, especially from affective disorders, is not referred to as differential diagnosis, but as differential typology, since the cause of schizophrenia is unknown. In the first place come the:

• Persistent delusional disorder (F 22)
• Acute psychosis (F23)
• Schizoaffective disorder (F25)

As well as the affective psychoses:

• Depression with psychotic symptoms (F32 / 33)
• Mania or bipolar disorder with psychotic symptoms (F30 / 31)

The distinction is usually made by taking two criteria into account, namely the course and the absence or predominance of symptom group 1 - 4 according to the ICD or the first-class symptoms according to Schneider. If the psychosis occurs quickly in the course of the disease, remits quickly and completely and then no further psychotic symptoms occur, the diagnosis of acute psychosis should be made (F23). If the patient has schizophrenic symptoms and depressive or manic symptoms of the same intensity, the diagnosis of schizoaffective disorder should be made (F25). In the event that the patient only experiences delusional symptoms and these persist for a long time, the diagnosis of a persistent delusional disorder should be made. If the delusion is short-lived and transient, an acute delusional psychotic disorder is diagnosed (F22 or F23. 3). If a patient develops psychotic and affective symptoms, but the symptoms from the group of affective disorders predominate, the diagnosis of an affective disorder is made (F3x). The occurrence of isolated symptoms such as hallucinations or a culturally adapted madness is not indicative of schizophrenia and, according to various authors, is not always considered a sign of disease.

Excursus: Classification of the so-called schizoaffective disorder

With the term "psychosis of the schizoaffective intermediate area", Janzarik described a disease in which schizophrenic and manic or depressive symptoms occur at the same time. This describes a disease that the ICD treats with the term "schizoaffective disorder" under F25.

This disease has been given different terms by other authors. Schneider spoke of "intermediate cases" between affective and schizophrenic psychoses, Kasanin spoke of "schizoaffective psychoses", Leonhard of "unsystematic" or " cycloid psychoses " and the Scandinavian school (Langfeldt) of "schizophrenic psychoses"

Karl Leonhard distinguished six main groups of endogenous psychoses:

• The three phasic psychoses (without the cycloids):
  • Unipolar manias
  • Unipolar Depression
  • Bipolar disease

• The cycloid psychoses: fear-happiness psychosis, excited-inhibited confusion psychosis, hyperkinetic-akinetic motility psychosis
• The unsystematic schizophrenia: affective paraphrenia, periodic catatonia, etc.
• The systematic schizophrenias: catatonias, hebephrenias and paraphrenias.

The cycloid psychoses should have a good prognosis and heal “defect-free”.

On the question of the diagnosis and prognosis of schizoaffective psychosis, Huber et al. Commented in the "Bonn Study". Here four types of psychosis in the schizoaffective intermediate range were found and their prognosis was overall significantly more favorable than that of the entire collective of the Bonn schizophrenia study. Huber describes this type of illness as "schizoaffective psychoses" according to Kasanin, Spitzer and Angst or "cycloid psychoses" according to Leonhard and Perris.

The correspondence between “cycloid psychoses” and “schizioaffective disorder” has been questioned by other authors. Michael Zaudig differentiates between two concepts of psychoses with a good prognosis, the traditional concepts of "bouffee delirante", "cycloid psychosis" and "schizoaffectives" according to Kazanin on the one hand and the "schizoaffective psychoses" according to the criteria of Kendell, Welner, DSM and ICD. According to Zaudig, there should be no agreement between the two groups. More recent work by Beckmann's group underscores the fact that the so-called “cycloid psychoses” are not part of the affective disorders (bipolar disorder).

In Mathias Berger's textbook, “schizoaffective disorder” is described as a disease in which there is uncertainty as to whether it can be assigned to affective or schizophrenic diseases. The concept of schizoaffective psychosis remains controversial. The Leohard classification with its concepts of cycloid psychosis and unsystematic schizophrenia tries to remedy this uncertainty. Different ways of classifying the schizoaffective disorder are discussed.

In the ICD, “cycloid psychosis” is not assumed to be identical to “schizoaffective disorder”. It is classified under “Other non-organic psychotic disorders” (ICD-10 F 28).

It can thus be stated that Leonhard differentiates between four groups of psychoses: the affective, the cycloid, the unsystematic and the systematic psychoses. In German psychiatry, Huber and Zaudig saw the correlation between the cycloid psychoses and the schizoaffective disorder of the ICD, and Beckmann et al. Accepted the cycloid psychoses as an independent group independent of the schizoaffective disorder and the bipolar disorders.

Summary

When patients report hallucinations and delusions and are anxious and worried, the acute psychotic episode of schizophrenia can be recognized by laypeople. But these crises usually only characterize the life of a person with schizophrenia for short periods of time. Regardless of the acute psychotic episodes, the experience of the patient is mostly characterized by deficit experiences: Depression, social disabilities and social stigmatization are just as much a part of the everyday life of the sick as hearing voices and delusional fears.

The assessment of the extent and the differentiation of all associated complaints not only requires experience and practice, but also an understanding of the examiner about common standards for assessing the various items. For this reason, survey instruments have been developed whose use requires special induction and training. The same applies to the operationalized diagnosis of diseases according to the international classification systems. The coordination of the survey instrument and the classification system (e.g. SCID and DSM) is particularly advantageous here.

By using such standardized procedures, a comparability of data in scientific studies is achieved in psychiatry, which makes the investigation of large numbers of cases possible in the first place. The aim of these standardized procedures is to establish evidence-based medicine in the treatment of schizophrenia.

See also

• Clinical schizophrenia concepts
• Symptoms of schizophrenia according to Bleuler
• Symptoms of schizophrenia according to Schneider
• Neurobiological Schizophrenia Concepts
• Subtyping of schizophrenia
• Onset and early course of schizophrenia
• Late schizophrenia
• Course of schizophrenia
• Therapy for schizophrenia

literature

• Mathias Berger (Ed.): Mental illnesses. Clinic and Therapy. 4th edition. Urban & Fischer, Munich 2012, ISBN 978-3-437-22483-6 .
• Heinz Häfner among others: Onset and early course of schizophrenic diseases. In: Joachim Klosterkötter (Ed.): Early diagnosis and early treatment of mental disorders . Springer, Berlin 1998, ISBN 3-540-64440-7 .
• Heinz Häfner: The riddle of schizophrenia. A disease is deciphered. 3. Edition. Beck, Munich 2005, ISBN 3-406-52458-3 , p. 76ff.
• Heinz Häfner: Schizophrenia: recognize, understand, treat . Beck, Munich 2010, ISBN 978-3-406-58797-9 .
• Gerd Huber, Gisela Gross: Psychiatry textbook for study and further education. 7th edition. Schattauer, Stuttgart / New York 2005, ISBN 3-7945-2214-1 .

Individual evidence

1. ↑ TO Jablensky et al.: Schizophrenia: Manifestations, incidence and course in different cultures. A World Health Organization ten-country study. In: Psychol. Med. (= Monograph Suppl. 20). Cambridge University Press, 1992.
2. ↑ H. Häfner et al.: Onset and early course of schizophrenic diseases. In: J. Klosterkötter: Early diagnosis and early treatment of mental disorders. Springer-Verlag, Berlin 1998, ISBN 3-540-64440-7 .
3. ^ Mathias Berger: Mental Illnesses. Clinic and Therapy. Urban & Fischer, Munich 2004, ISBN 3-437-22480-8 , p. 468ff.
4. ^ E. Bleuer: Dementia praecox or group of schizophrenias. Deuticke, Leipzig / Vienna 1911.
5. ↑ ICD-10 checklists
6. ↑ DIA-X Diagnostic Expert System for Mental Disorders
7. ↑ Heinz Häfner: The riddle of schizophrenia. A disease is deciphered. 3. Edition. CH Beck, Munich 2005, ISBN 3-406-52458-3 , p. 76 ff.
8. ^ NC Andreasen, S. Olsen: Negative v positive schizophrenia. Definition and validation. In: Arch Gen Psychiatry . 39 (7), July 1982, pp. 789-794. PMID 7165478
9. ↑ Heinz Häfner: The riddle of schizophrenia. A disease is deciphered. 3. Edition. CH Beck, Munich 2005, ISBN 3-406-52458-3 , p. 79 ff.
10. ↑ K. Schneider: Clinical Psychopathology. 14th edition. With a comment by Huber G and Gross. G. Thieme. Stuttgart 1992.
11. ^ Gerd Huber: Psychiatry textbook for study and further education. Schattauer, Stuttgart 1999, ISBN 3-7945-1857-8 , pp. 259 f. and 303 ff.
12. ↑ H. Häfner et al: Onset and early course of schizophrenia. In: H. Häfner et al .: Search for the causes of schizophrenia. Vol. III, Springer, Berlin 1995, pp. 43-66.
13. ↑ H. Olbrich et al.: Schizophrenia and other psychotic disorders. In: Mathias Berger (Ed.): Mental illnesses. Clinic and Therapy. Urban & Fischer, Munich 2004, ISBN 3-437-22480-8 , p. 485.
14. ^ SR Kay: The positive and negative syndrome scale (PANSS) for schizophrenia. In: Schizophr Bull. 13 (2), 1987, pp. 261-276. PMID 3616518
15. ^ NC Andreasen: The Diagnosis of Schizophrenia. In: Schizophrenia Bulletin. 13, 1987, pp. 9-22. PMID 3496659
16. ^ TJ Crow: The molecular pathology of schizophrenia. More than one disease process. In: British medical journal. 280, 1980, pp. 66-68. PMID 6101544 (full text)
17. ↑ S. Tosato, P. Dazzan: The psychopathology of schizophrenia and the presence of neurological soft signs: a review. In: Curr Opin Psychiatry. 18 (3), May 2005, pp. 285-288. PMID 16639153
18. ↑ LE Hong: Familial aggregation of eye-tracking endophenotypes in families of schizophrenic patients. In: Arch Gen Psychiatry. 63 (3), Mar 2006, pp. 259-264. PMID 16520430
19. ^ PE Bestelmeyer: Global visual scanning abnormalities in schizophrenia and bipolar disorder. In: Schizophr Res. 87 (1-3), Oct 2006, pp. 212-222. Epub 2006 Jul 24. PMID 16860975
20. ^ Neurological soft signs in the clinical course of schizophrenia: results of a meta-analysis
21. ↑ TD Gould, II Gottesman: Psychiatric endophenotypes and the development of valid animal models. In: Genes Brain Behav. 5 (2), Mar 2006, pp. 113-119. PMID 16507002
22. ↑ BI Turetsky: Neurophysiological endophenotypes of Schizophrenia: The Viability of Selected Candidate Measures. In: Schizophr Bull. 29 Nov 2006. PMID 17135482
23. ↑ World Health Organization. Edited by H. Dilling, W. Mombour and MH Schmidt: International Classification of Mental Disorders. ICD-10 Chapter V (F). Clinical diagnostic guidelines. 5th, revised and supplemented edition. taking into account the changes according to ICD-10-GM 2004/2005. Verlag Hans Huber, Bern 2005, ISBN 3-456-84124-8 .
24. ↑ World Health Organization. H. Dilling et al. (Ed.): International classification of mental disorders. ICD-10 Chapter V (F). Diagnostic criteria for research and practice. 3rd, corrected edition. Verlag Hans Huber, Bern 2004, ISBN 3-456-84098-5 .
25. ↑ World Health Organization. Pocket Guide to the ICD-10 Classification of Mental Disorders. With glossary and diagnostic criteria ICD-10: DCR-10. Translated and edited by H. Dilling and HJ Freyberger from the English-language Pocket Guide by JE Cooper. 3rd completely revised and expanded edition. taking into account the German Modification (GM) of the ICD-10. Verlag Hans Huber, Bern 2006, ISBN 3-456-84255-4 .
26. ↑ World Health Organization. Horst Dilling et al. (Ed.) Lexicon for the ICD-10 classification of mental disorders. Terms of psychiatry and mental health, especially the abuse of psychotropic substances. Verlag Hans Huber, Bern 2002, ISBN 3-456-82679-6 .
27. ^ HJ Freyberger, H. Dilling (Ed.) With the collaboration of Silke Kleinschmidt and Ute Siebel: Fallbuch Psychiatrie. Case reports on Chapter V (F) of ICD-10. 2nd reprint 1999. Verlag Hans Huber, 1993, ISBN 3-456-82355-X .
28. ↑ Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Translated from the fourth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders. German adaptation and introduction by Henning Saß, Hans-Ulrich Wittchen and Michael Zaudig. Editorial coordination: Isabel Houben. Hogrefe Publishing House. Göttingen 1996, ISBN 3-8017-0810-1 .
29. ↑ Diagnostic and Statistical Manual of Mental Disorders - Text revision (DSM-IV-TR). German adaptation and introduction by Henning Saß, Hans-Ulrich Wittchen and Michael Zaudig. Hogrefe Publishing House. Goettingen 2003.
30. ↑ JE Mezzich: multiaxial diagnosis and international classification in psychiatry. In: Fundamenta Psychiatrica. 3, 1992, pp. 150-153. (Not a Pub Med hit. Maybe: PMID 3214699 or: PMID 2249797 )
31. ↑ M. Rutter, E. Taylor (Eds.): Child and adolescent psychiatry. 4th edition. Blackwell, Oxford 2002, pp. 3-17.
32. ↑ M. Rutter, S. Lebovici, L. Eisenberg, AV Sneznevskij, R. Sadoun, E. Brooke, TY Lin: A tri-axial classification of mental disorders in childhood. An international study. In: J Child Psychol Psychiatry. 10 (1), Sep 1969, pp. 41-61. PMID 4188614 .
33. ↑ World Health Organization. Pocket Guide to the ICD-10 Classification of Mental Disorders. With glossary and diagnostic criteria ICD-10: DCR-10. Translated and edited by H. Dilling and HJ Freyberger from the English-language Pocket Guide by JE Cooper. 3rd completely revised and expanded edition. taking into account the German Modification (GM) of the ICD-10. Verlag Hans Huber, Bern 2006, ISBN 3-456-84255-4 , p. 495.
34. ↑ C. Scharfetter: Occultism, parapsychology and the esoteric from the perspective of psychopathology. In: Fortschr Neurol Psychiatr. 66 (10), Oct 1998, pp. 474-482. PMID 9825253
35. ↑ W. Janzarik: Structural dynamics foundations of psychiatry. Enke, Stuttgart 1988.
36. ^ N. Retterstol: The Scandinavian concept of reactive psychosis, schizophreniform psychosis and schizophrenia. Psychiatr. In: Clin. 11, 1978, pp. 180-187. PMID 740918 .
37. ^ K. Leonhard: Division of endogenous psychoses and their differentiated etiology. Aufbau-Verlag, 1966 (Thieme 1995 (publisher Helmut Beckmann), Springer 1999 (publisher Helmut Beckmann))
38. ↑ G. Huber: Psychiatry. Textbook for study and further education. Schattauer, 1999, p. 250.
39. ↑ G. Gross, G. Huber, B. Armbruster: Schizoaffective psychoses - long-term prognosis and symptomatology. In: A. Marneros , MT Tsuang, (Ed.): The schizoaffective psychoses. Springer, Berlin 1986.
40. ↑ G. Huber: Psychiatry. Textbook for study and further education. Schattauer, 1999, p. 251.
41. ^ C. Perris: The importance of Karl Leonhard's classification of endogenous psychoses. In: Psychopathology. 23 (4-6), 1990, pp. 282-290. PMID 2084782
42. ↑ M. Zaudig: Cycloid psychoses and schizoaffective psychoses-a comparison of different diagnostic classification systems and criteria. In: Psychopathology. 23 (4-6), 1990, pp. 233-242. PMID 2084775
43. ↑ B. Jabs et al.: Cycloid psychoses as atypical manic-depressive disorders: Results of a family study. In: Neurologist. 77 (9), Sep 2006, pp. 1096-1104. PMID 15546641
44. ↑ B. Pfuhlmann: Cycloid psychoses are not part of a bipolar affective spectrum: results of a controlled family study. In: J Affect Disord. 83 (1), Nov 15, 2004, pp. 11-19. PMID 15546641
45. ↑ M. Berger: Mental illnesses. Clinic and Therapy. Urban & Fischer, 2004, p. 524.
46. ↑ H. Dilling (Ed.): International Classification of Mental Disorders. ICD-10 Chapter V (F). 5th edition. Verlag Hans Huber, 2005, p. 126.

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This version was added to the list of articles worth reading on June 30, 2007 .